The technologies nowadays innovate and advance by time, and all kinds of electronic products such as personal computer, personal digital assistant, server, disk array storage device, printer, notebook and smart phone etc. keep emerging. Transmitting electronic information such as voice, image, email and database etc. via electronic products makes the communication between enterprises more rapid and convenient, thereby transforms the conventional business model into global aspect and increases the need of the storage devices conspicuously.
To fulfill the needs of the enterprises, the manufacturers of storage device have invented the disk array storage device, which is capable of storing massive data and with high security. Besides, the disk array storage device may be connected to several servers simultaneously, so the network services provided by each server are able to access it respectively. Hence, the quality and performance of the disk array storage device is the key to the operation of the servers.
The disk array storage device processes each access request from each server in the order of receipt. In other words, only when the processing of the present access request is completed will the next access request be processed. And because the disk array storage device fails to specify the priority of the access requests from the servers according to specific criteria (such as the importance of the request), there would be problems like poor network service quality and unstable performance of the servers etc.